It is known to provide wheelchairs with leg rests secured to the frame of the wheelchair, the leg rests including foot rests for supporting an occupant's feet. It is further known to pivotally couple such leg rests to the wheelchair, such that the leg rest and foot rest is movable between a lowered position in which the user's feet are positioned for operation of the wheelchair and a raised position, or positions, in which the user's feet are elevated from the lowered position.
Typically, the axis of rotation for the pivoting leg rest is offset from the axis of rotation of an occupant's legs, located at the knee joint. This offset between the two axes of rotation tends to drive an occupant's feet toward the user's knee as the leg rest is pivoted to raise the foot rest, potentially causing an undesirable compression of an occupant's legs.
To address the undesirable effects of the offset between the rotational axes, prior art wheelchairs have included foot rests that are extendable with respect to a remainder of the leg rest. Typically, such wheelchairs include a lower foot rest support member telescopically received by an upper pivoting member. Examples of such wheelchairs are shown in U.S. Pat. No. 5,033,793 to Quintile; U.S. Pat. No. 5,328,247 to Lovins; and U.S. Pat. No. 5,259,664 to Cottle.
A need exists for a powered extendible and retractable leg rest having a novel, simple, and robust mechanism to extend and retract the leg rest in accordance with rotation of the leg rest.